The present invention relates to an image forming apparatus and an image forming method capable of smoothly and reasonably conducting image formation in case of using a lens (lenses) of which optical magnification is minus.
Generally, a toner image forming means of electrophotographic type comprises a photoreceptor as an image carrier having a photosensitive layer on its outer surface, a charging means for uniformly charging the outer surface of the photoreceptor, an exposing means for selectively exposing the outer surface, uniformly charged by the charging means, to form an electrostatic latent image, and a developing means for applying a toner as a developer on the electrostatic latent image, formed by the exposure means, to form a visible image (toner image).
As a tandem-type image forming apparatus for forming a color image, there is an image forming apparatus of a type employing an intermediate transfer belt. The image forming apparatus comprises a plurality of (for example, four) toner image forming means as mentioned above which are disposed relative to the intermediate transfer belt. Toner images on the photoreceptors formed by the unicolor toner image forming means are transferred sequentially to the intermediate transfer belt so that the toner images of plural colors (for example, yellow, cyan, magenta, and black) are superposed on each other on the intermediate transfer belt, thereby forming a color image on the intermediate transfer belt.
In the tandem-type color image forming apparatus (printer), it is known to use a light emitter array as the exposure means (line head). For example, in an example disclosed in JP-A-2001-63139, light emitted from light emitting elements which are two-dimensionally aligned in a light emitter array is enlarged by a single lens and a photoreceptor is irradiated with the enlarged light to form a latent image. On the other hand, in an example disclosed in JP-A-8-166555, the writing position on an image surface (image carrier) is inverted from the position of a light emitting source by microlens arrays which are aligned in the longitudinal direction of an LED array chip.